Basics of Waves
Waves are constantly moving disturbances through a certain medium. Waves carries out energy but do not moves matter. For instance, in a baseball game, the batter hits the ball with kinetic energy. However, the ball never comes back to the original position. In this case, energy and matter are both moved.

Types of Waves:
  • Transverse Waves: example might be the stadium wave.
transverse.gif
  • longitudinal waves: an example of a longitudinal wave is the sound wave.
longitudinal.gif

Another way to categorize waves is by using the ability or inability to transmit energy through a vacuum.

  • Electromagnetic waves: these are waves which can pass enery through a vacuum. An example is the light wave. If the light from the sun could not go through the space, vacuum, there would be no life on earth. Hence, all light waves are electromagnetic waves.
  • Mechanical waves: these are waves which cannot go through a vacuum. Example is the sound wave. No medium, no sound.

For further information check out: http://www.glenbrook.k12.il.us/gbssci/Phys/Class/waves/u10l1a.html


Blu-ray Disk
The way it writes and reads the disk is by using the blue rays. Unlike the normal DVD's, Blu-ray disks uses shorter wavelength (405nm). Normal DVD's uses red lasers whchi has the wavelength of 650nm. A dual layered blu-ray disk can store up to 50 GB.
9-18-07-lthbd-r.jpg
Mitsubishi's BD-R



Multiple-Slit Experiment

Data Table:


Gratings (lines/mm)
Distance (r)
Separation (s)
Calculated
Width (m)

Distance (r)
Separation (s)
Calculated Width (m)
25
1m
1.6cm
4.0625 E-5
2m
3.4cm
3.82352941 E-5
50
1m
3.25cm
2 E-5
2m
6.8cm
1.9117647 E-5
100
1m
6.6cm
9.84848484 E-6
2m
13.4cm
9.70149253 E-5
The calculated width does equal the "lines/mm."

Conclusion: As the distance between the diffraction grating and the wall increased the seperation between the dots of diffracted laser points got larger.